Scordatura is the tuning of a string instrument differently from the conventional tuning. The usual purposes are to create special effects or unusual chords or timbres, or to make some passages easier to play. It is common to notate the finger position as if played in conventional tuning, while the resulting pitch is altered. Scordatura has a long history, beginning at least in the Baroque era, and among the composers who have used it are Bach, Vivaldi, Stravinsky and Corigliano.